In the vast majority of clinical procedures and operations, it is essential to ensure the sterility of the instruments and/or other aids used. For this reason, sterile containers (also referred to as sterilization containers) are used, which are loaded/filled with medical instruments, for example. The sterile container is then heated in the loaded state in an autoclave for a specified period of time to a specified sterilization temperature until any microorganisms adhering to the medical instruments have been killed.
Heating the container and its contents with steam during steam sterilization leads to the formation of condensate inside the container, which prolongs the drying time of the sterile materials or in the worst case even leads to moist sterile materials upon removal. A drain opening in the sterile container is therefore advantageous, as the condensate can drain off again as soon as it is formed, thus facilitating drying. In addition, a sterile filter is required in the sterile container to prevent germs from entering the receiving space of the sterile container after the sterilization process. In addition to the opening for gas exchange, an additional opening in the container wall is therefore necessary to discharge the condensate.
Such sterile containers comprising a sterile filter and a drain opening are already known from the prior art. For example, DE 197 53 671 A1 discloses a sterile container comprising a filter disc in its cover. In addition, openings are provided in the cover and in the base, which are sealed by sealing lips. If the pressure difference between the inside and outside of the container exceeds a certain value, the sealing lips release the openings and a fluid can be fed to or discharged from the sterile container. Such an additional opening or even just one additional interface carries an additional risk in terms of sterilization. In addition, this interface must be controlled from time to time in addition to other components of the sterile barrier, which increases costs and also the amount of work involved.
Furthermore, DE 20 2010 003 204 U1 describes a fluid outlet for a container which makes it possible to close or release an opening in a container base depending on the pressure. For this purpose, a pressure chamber is provided as an actuator, which chamber is formed by a cylindrical bellows and two covers. One of the two covers is firmly connected to a covering and the other is designed so that it is able to completely close the opening in the container base but does not touch the container base in the initial position. However, if the pressure in the pressure chamber exceeds the ambient pressure, the bellows stretches and presses the cover against the opening so that it is closed. A similar configuration is disclosed in DE 41 11 077 C2, but here the opening in the container base is closed or released depending on the temperature and not on the pressure.
Since the systems described above always either close or open the outlet opening for the condensate, it is not possible to integrate a filter element into such an outlet valve arrangement. It is therefore an object of the present invention to provide a filter system which has an additional outlet function.